Key fact Magnification of the microscope = magnification of eyepiece × magnification of objective So, if the magnification of an eyepiece is ×10 and the objective is ×4, the magnification of ...
We can use microscopes to look at objects too small ... the ×4 objective lens, and the ×10 eyepiece lens before it gets to your eye. This makes the image 4 × 10 = 40 times bigger.